Are there visual signs? sounds? Thanks!
the only warning sign I know of is that the battery gets drained and the car won’t start.
Alternator warning light flashing or on steady.
CEL light may be on.
Squealing and gauge fluctuating.
Vehicle lights flickering.
Battery running down quickly after a charge.
Yeah I would agree but just depends on what is going bad. If the bearings get worn, you can get a noise or the shaft will be loose. If the brushes go bad or the voltage regulator, you can get reduced voltage output or fluctuating, which will either turn the light on or show up on the guage. If you get a failure of the armature or the diode trio, you’ll get no output at all and the light will be on or the voltage guage will show battery voltage only. Dim or flickering lights are a first clue.
The alternator failed in my 93 Caprice with no warning. I started it up in the morning and the Alt light did not go off. The alternator did not show any signs of trouble before it failed.